JP2006064493A - Coating method and coating machine for bent tube inner circumferential surface of reactor containment vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for recoating an inner circumferential surface of an existing bent tube in a reactor containment vessel. <P>SOLUTION: A hoist 32 is disposed in a dry well 12. A coating machine 36 is disposed in a suppression chamber 14. A pulley 35 is disposed in a position below a cover plate 26 on a diaphragm floor 16. A wire rope 38 of the hoist 32 is put through a gap 30 between legs 24, and through a space 28 between an under surface of the cover plate 26 and an upper end opening 20a of the bent tube 20, is looped over the pulley 35, is put through the tube 20, and is connected to the coating machine 36. The wire rope 38 is wound up to lift the coating machine 36 into the bent tube 20. The inner circumferential surface 20b of the bent tube is painted by spraying a paint 42 from a nozzle 40 of the coating machine 36 toward the inner circumferential surface 20b of the bent tube while vertically moving the coating machine 36 by the hoist 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and a coating machine for painting an inner peripheral surface of an existing vent pipe in a reactor containment vessel so that a painting operation can be automated.

  Nuclear power plant suppression chambers need to be repainted regularly. A plurality of vent pipes are arranged in the suppression chamber, and the inner and outer peripheral surfaces of the vent pipes are also subject to repainting. The vent pipe generally has a diameter of several tens of centimeters, and when recoating the inner peripheral surface, conventionally, a scaffold is built into the vent pipe from the floor in the suppression chamber, and an operator follows the scaffold and enters the inside of the vent pipe. I was painting.

In addition, there exists the technique described in the following patent document 1 as a repainting method of a suppression chamber.
JP 2000-314796 A

  According to the above-described conventional coating method in the vent pipe, the worker has to enter the vent pipe in a poor working environment and perform the work, which is a severe and dangerous work.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a coating method and a coating machine for the inner peripheral surface of a vent pipe that can automate the coating operation.

  In the painting method of the present invention, the vent pipe is vertically arranged through the diaphragm floor separating the dry well and the suppression chamber, the upper end of the vent pipe is opened and communicated with the dry well, and the lower end of the vent pipe is opened. A plurality of legs are fixedly arranged on the upper surface of the diaphragm floor so as to surround the upper end opening of the vent pipe, and a cover plate is attached to the upper end of the leg. The upper end opening of the vent pipe is fixedly arranged so as to cover the upper end opening of the vent pipe with a space upward, and the upper end opening of the vent pipe is formed between the space between the lower surface of the cover plate and the plurality of A method of coating the inner peripheral surface of a vent pipe in a containment vessel having a structure communicating with a dry well through a gap between legs, the hoist Disposing a coating machine in the suppression chamber, disposing a rope hook such as a pulley below the cover plate, and connecting the rope of the hoisting machine between the legs and the lower surface of the cover plate And through the space between the upper end opening of the vent pipe and the rope hanger, through the inside of the vent pipe, connected to the coating machine, hoisting the rope, lifting the coating machine into the vent pipe, and painting The paint is sprayed from the nozzle of the machine toward the inner peripheral surface of the vent pipe, and the inner peripheral surface of the vent pipe is painted by moving the vertical position of the coating machine by the hoisting machine.

  In the painting method of the present invention, after the rope of the hoisting machine is connected to the painting machine, the rope is wound up, the painting machine is lifted up to the vicinity of the upper end portion in the vent pipe, and the paint is vented from the nozzle of the painting machine. The inner peripheral surface of the vent pipe can be painted by gradually lowering the coating machine while spraying in the entire peripheral direction of the inner peripheral surface of the pipe. Further, in the painting method of the present invention, the rope hanger is attached to a rope hanger attachment jig, and the rope hanger attachment jig is opened between the lower surface of the cover plate and the upper end of the vent pipe through the gap between the legs. The rope hanger mounting jig can be detachably fixed to the peripheral edge of the cover plate at a plurality of locations by mounting brackets. In the painting method of the present invention, a spray dust receiving member having a size that substantially closes the inner diameter of the vent pipe is attached and disposed at a position below the spray range of the nozzle of the coating machine, and the spray dust receiving member is disposed during painting. The member can be lowered together with the coating machine so that the descending spray dust is received by the spray dust receiving member.

  A coating apparatus according to the present invention is a reactor containment vessel having a structure in which a vent pipe is vertically arranged through a diaphragm floor that partitions a dry well and a suppression chamber, and is suspended in a vent pipe by a rope so as to be lifted and lowered. A coating machine for painting an inner peripheral surface of a vent pipe, a rotation support portion, a rotation portion rotatably connected to the rotation support portion, and a rotation shaft of the rotation portion above the rotation portion. And a suspension support portion connected to the rotation portion so as to be relatively rotatable with the rotation portion, and the rotation support portion presses the pressing contact member against the inner peripheral surface of the vent pipe at a plurality of locations in the circumferential direction. The rotation support part itself is allowed to move in the vent pipe axis direction while suppressing the rotation of the rotation support part itself in the direction around the vent pipe axis, and the rotation part is connected to the axis of the vent pipe. Rotation is possible with almost the same position The rotating part is provided with a nozzle for injecting paint toward the inner peripheral surface of the vent pipe, and the paint sprayed from the nozzle with the rotation of the rotating part. And the suspension support portion is connected to the rope and suspends and supports the rotation portion so as to be relatively rotatable about its rotation axis, and the rotation support portion. And the said suspension support part is arrange | positioned outside the injection range of the said nozzle.

  In the coating apparatus of the present invention, a spray dust receiving member having a size that substantially closes the inner diameter of the vent pipe can be mounted and disposed at a position below the nozzle injection range. In the coating apparatus of the present invention, the pressing contact member can be pressed and contacted to the inner peripheral surface of the vent pipe by a caster that rotates in the horizontal direction.

  According to this invention, the painting operation in the vent pipe can be automated.

  Embodiments of the present invention will be described below. First, FIG. 2 shows a structural example of a reactor containment vessel to which the present invention can be applied. This shows a boiling water Mark II type reactor. In the reactor building 10, a dry well 12 and a suppression chamber 14 are formed in the reactor containment vessel 11 by being partitioned by a diaphragm floor 16. A reactor pressure vessel 18 is disposed in the dry well 12. In the suppression chamber 14, a plurality of (for example, 108) cylindrical and straight tubular vent pipes 20 are vertically disposed through the diaphragm floor 16. The upper end portion of the vent pipe 20 is opened and communicated with the dry well 12, and the lower end portion of the vent pipe 20 is opened and communicated with the suppression chamber 14. During operation of the nuclear reactor, water is filled in the suppression chamber 14 to form a suppression chamber pool 22. The lower part of the vent pipe 20 is inserted into the suppression chamber pool 22. With such a structure, when the reactor is operated, the steam pipe is broken in the dry well 12, the steam leaks, and when the pressure in the dry well 12 becomes high, the leaked steam passes through the vent pipe 20. The pressure is released to the suppression chamber pool 22 and the pressure in the dry well 12 is lowered.

  The structure of the location where the vent pipe 20 on the upper surface of the diaphragm floor 16 penetrates is shown in FIG. The upper end portion of the vent pipe 20 penetrates the diaphragm floor 16 and opens to the dry well 12 at a position slightly above the floor surface of the diaphragm floor 16. On the upper outer peripheral surface of the vent pipe 20, a flange 23 projecting outward in a ring shape is formed at a position in the middle of passing through the diaphragm floor 16. When the flange 23 is embedded and fixed in the diaphragm floor 16, the vent pipe 20 is fixedly supported on the diaphragm floor 16. The vent pipes 20 are connected to each other in the suppression chamber 14. At the position where the vent pipe 20 penetrates the diaphragm floor 16, the outer peripheral surface of the vent pipe 20 and the inner peripheral surface of the through hole of the diaphragm floor 16 are hermetically sealed. A jet deflector 21 is fixedly disposed on the diaphragm floor 16 so as to cover the vent pipe 20. The jet deflector 21 includes a leg 24 and a cover plate 26. That is, on the upper surface of the diaphragm floor 16, a plurality of legs 24 are arranged in a circle so as to surround the periphery of the upper end opening 20 a of the vent pipe 20. The lower end of the leg 24 is embedded in the diaphragm floor 16 and fixed to the upper surface of the flange 23. A circular cover plate 26 is fixedly disposed at the upper end portion of the leg 24 so as to cover the upper end opening 20 a of the vent pipe 20. A space 28 is formed between the upper end opening 20 a of the vent pipe 20 and the lower surface of the cover plate 26. Thereby, the upper end opening 20 a of the vent pipe 20 communicates with the dry well 12 through the space 28 between the lower surface of the cover plate 26 and the gap 30 between the legs 24.

A procedure for repainting the inner peripheral surface 20b of the vent pipe 20 having the structure shown in FIGS. 2 and 3 will be described with reference to FIG. In addition, before repainting, the old coating of the vent pipe inner peripheral surface 20b is removed using a technique such as sandblasting. Here, it is assumed that the old paint has already been removed.
(1) Since the gap 30 between the legs 24 and the space 28 between the upper end opening 20a of the vent pipe 20 and the lower surface of the cover plate 26 are narrow, the coating machine 36 is connected to the vent pipe 20 from the vent pipe upper end opening 20a side. Cannot be inside. Therefore, first, in the suppression chamber 14, the coating machine 36 is disposed on the floor 34 at a position vertically below the vent pipe 20. Further, a hoisting machine 32 is disposed on the floor of the diaphragm floor 16 in the dry well 12. Further, the pulley 35 is disposed at a substantially central position on the lower surface side of the cover plate 26. The wire rope 38 fed out from the hoisting machine 32 passes through the gap 30 between the legs 24, hangs on the pulley 35, hangs down on the central axis L in the vent pipe 20, and is connected to the upper part of the coating machine 36.
(2) The hoisting machine 32 is driven in the hoisting direction, the wire rope 38 is hoisted, and the coating machine 36 is at the highest point in the vent pipe 20 (a height position at which the upper end position of the inner peripheral surface of the vent pipe 20 can be painted). Lift up to.
(3) Next, coating is performed by spraying the coating 42 from the spray nozzle 40 of the coating machine 36 toward each direction of the vent pipe inner peripheral surface 20b. As a method of painting the entire circumference of the vent pipe inner peripheral surface 20b, a plurality of spray nozzles 40 are fixedly arranged so that the injection ranges overlap in the respective directions of the vent pipe inner peripheral surface 20b. A method of spraying the paint 42, a method in which one or a plurality of spray nozzles 40 are rotatably arranged, and a method of spraying the paint 42 from the spray nozzle 40 while rotating the spray nozzle 40 in the entire circumferential direction of the vent pipe inner peripheral surface 20b. Can be considered. While spraying the paint 42 from the spray nozzle 40, the hoisting machine 32 is driven in the lowering direction and the wire rope 38 is gradually lowered at a constant speed, thereby coating the vent pipe 20 from above to below. Can do. When the painting is completed up to the lower end of the vent pipe 20, the spraying of the paint 42 from the spray nozzle 40 is stopped, the wire rope 38 is further lowered, and the coating machine 36 is landed on the floor 34. Thus, the coating of the inner peripheral surface 20b of one vent pipe 20 is completed. Therefore, the wire rope 38 is removed from the coating machine 36, the hoisting machine 32 is driven, and the wire rope 38 is wound up and collected. In this way, the vent pipe inner peripheral surface 20b can be automatically coated. When the coating of the inner peripheral surface 20b for one vent pipe 20 is completed, the process moves to the next vent pipe 20 and the inner peripheral surface 20b is coated in the same manner as described above. When coating is performed by rotating one spray nozzle 40 in the entire circumferential direction of the vent pipe inner peripheral surface 20b, for example, a state in which the rotation axis of the spray nozzle 40 is substantially coincident with the central axis L of the vent pipe 20 Then, the nozzle 42 is continuously rotated at a constant speed, and the paint 42 is sprayed from the spray nozzle 40 in the horizontal direction at a constant spray amount to coat the inner peripheral surface 20b of the vent pipe over the entire circumference. At this time, while continuously spraying the coating material 42 from the spray nozzle 40, the hoisting machine 32 is driven in the lowering direction to move the wire rope 38 at a constant speed (the vertical spraying range exceeds each other for each turn). By gradually lowering at a wrapping speed), the coating can be continuously performed spirally without any gaps from the top to the bottom of the vent pipe 20.

  Next, a specific example of a coating machine in the case where coating is performed by rotating one spray nozzle 40 in the entire circumferential direction of the vent pipe inner peripheral surface 20b will be described. FIG. 4 shows the overall structure of the coating machine 36 (shown in a state where it is suspended from the wire rope 38 and accommodated in the vent pipe 20). Moreover, the AA arrow line view of FIG. 4 is shown in FIG. The coating machine 36 includes a rotation support portion 44 configured in a substantially cylindrical shape, a rotation portion 46 connected and supported on the upper side of the rotation support portion 44 so as to be rotatable on the center axis thereof, and an upper side of the rotation portion 46. And a suspension support portion 48 that is rotatably connected coaxially with the rotation axis of the rotation portion 46 and supports the rotation portion 46 so as to be relatively rotatable. The rotation support portion 44 includes a top plate 50 and a bottom plate 52 that are formed in a circular shape so as to substantially block the inner diameter of the vent pipe 20, and a connecting rod 54 that connects the top plate 50 and the bottom plate 52 to each other. A framework is constructed. The top plate 50 constitutes a spray dust receiving member that receives the spray dust 42a that falls out of the paint 42 sprayed from the spray nozzle 40 without adhering to the vent pipe inner peripheral surface 20b during painting. The connecting rod 54 is composed of a square pipe or the like. The connecting rod 54 has two gaps 56 each having a predetermined width at a plurality of locations (three or more locations, four locations in the illustrated example) at equal intervals in the circumferential direction of the peripheral portions of the top plate 50 and the bottom plate 52. Are arranged in parallel. The top plate 50 and the bottom plate 52 are arranged horizontally, and the connecting rod 54 is arranged vertically.

  A rubber caster 58 is rotatably supported by the connecting rods 54 and 54 at both sides of the gap 56 between the two connecting rods 54 and 54 at respective positions in the circumferential direction, and the outer peripheral surface is connected to the connecting rod 54. , 54 in a state of projecting outward from the outer surface of each. The rotation shaft 58a of the rubber caster 58 is formed in the horizontal direction (direction parallel to the tangent to the vent pipe inner peripheral surface 20b at the position where the outer peripheral surface of the rubber caster 58 faces). The diameter of the circle in contact with the outer peripheral surface of all the rubber casters 58 is set to be approximately the same as the inner diameter of the vent pipe 20.

  Arms 60 are accommodated and arranged on the upper portions of the gaps 56 between the two connecting rods 54 and 54 at respective positions in the circumferential direction. The arm 60 is rotatably supported by a rotation shaft 60a in a horizontal direction (a direction parallel to the rotation shaft 58a of the rubber caster 58 located below the shaft) supported between the connecting rods 54 and 54. A rubber caster 64 is attached to the surface of the arm 60 on the upper side of the rotating shaft 60a and facing outward. The rotation shaft 64a of the rubber caster 64 is formed in a horizontal direction (a direction parallel to the rotation shaft 60a of the arm 60). One end of a tension spring 66 is connected to the surface of the arm 60 on the lower side of the rotating shaft 60a and facing inward. The other ends of the tension springs 66 are connected to each other in a tensioned state via spring restraining rings 68. Accordingly, each arm 60 is rotated about the rotation shaft 60a by the pulling force of the tension spring 66, and the upper rubber caster 64 protrudes outward. Therefore, in a state where the coating machine 36 is accommodated in the vent pipe 20, the outer peripheral surface of each rubber caster 64 comes into contact with the inner peripheral surface 20b of the vent pipe with an appropriate pressing force. With such an arrangement of the rubber casters 64, the rotation support portion 44 is movable in the axial direction of the vent pipe 20 in a state in which the rotation of the vent pipe 20 around the axis L is suppressed. At this time, the lower rubber caster 58 comes into contact with the vent pipe inner peripheral surface 20b and suppresses the rotation support portion 44 from being inclined.

  In the rotation support portion 44, an air operation valve 70 for controlling supply / stop of paint by air pressure, a strainer 72, a rotation drive mechanism 74 for the rotation portion 46, and the like are mounted. The rotation drive mechanism 74 is attached to the lower surface of the central portion of the top plate 50 and is formed such that the rotation axis of the rotation portion 46 coincides with the central axis of the top plate 50 (and hence the central axis L of the vent pipe 20). . From the paint hose 41, the paint is pumped from an airless pump 173 (FIG. 13) described later and supplied to the air operation valve 70. The air hose 43 is pumped with valve operation air and supplied to the air operation valve 70. By operating the supply of the valve operating air with a control box 175 (FIG. 13), which will be described later, the opening / closing of the air operating valve 70 is switched, and the discharge / stop of the paint is controlled. The paint discharged from the air operation valve 70 is filtered by the strainer 72 (100 mesh) through the paint hose 37, guided into the rotation drive mechanism 74 through the three-way valve 47 and the paint hose 49, and further rotated. The spray nozzle 40 is sprayed through 46 spray nozzle tubes 39. The three-way valve 47 switches the flow path when cleaning the inside of the strainer 72 and discharges the drainage liquid through the hose 51. Air for driving the rotary drive mechanism 74 is pumped from the air hose 45 and supplied to the air motor 133.

  A magnetic sensitive switch 53 such as a reed switch is disposed on the top surface of the top plate 50 of the rotation support portion 44. A magnet 55 is disposed on the side surface of the rotating portion 46 so as to face the magnetic sensitive switch 53. These magnetic sensitive switch 53 and magnet 55 constitute a magnetic switch 57. As a rotation sensor, the magnetic switch 57 detects the rotation of the rotating unit 46 and outputs one pulse signal per rotation. The output signal of the magnetic switch 57 is sent to a control box 175 (FIG. 13) to be described later via a signal line 59. A hole 61 is formed in the central portion of the bottom plate 52 of the rotation support portion 44, and the hoses 41, 43, 45, 51 and the signal line 59 are drawn out below the rotation support portion 44 through the hole 61.

  Next, a detailed configuration of the rotation drive mechanism 74 will be described with reference to FIGS. A rotation drive mechanism mounting jig 76 is fixed to the lower surface of the top plate 50 with a plurality of screws 78. The upper casing 80 of the rotation drive mechanism 74 is attached to the attachment jig 76 by a plurality of screws (not shown). As shown in an exploded view in FIG. 7, the rotation drive mechanism 74 includes an upper casing 80 and a lower casing 82, which are detachably connected to each other by a plurality of screws 63. A recess 84 having a circular planar shape is formed in the lower casing 82, and a threaded through hole 86 is formed on the central axis L thereof. On the lower surface of the lower casing 82, the upper portion 88 a of the hose attachment nipple 88 is screwed and fixed to the through hole 86. A nut 49 a at the end of the paint hose 49 is screwed and fixed to the lower portion 88 b of the hose attachment nipple 88. A through hole 88 c is formed in the hose attachment nipple 88.

  In FIG. 7, a gland packing 92, a spring pressing washer 94, a spring 96, a spring pressing washer 100, and a bearing 102 are accommodated in the recess 84 of the lower casing 82 in this order. The bearing 102 is fixed by fitting the outer ring 102 a into the recess 84. A shaft portion 104 a protruding from the lower surface of the shaft gear 104 is fitted and fixed to the inner ring 102 b of the bearing 102. Thus, the shaft gear 104 is held so as to be rotatable about the axis L with respect to the lower casing 82. A concave portion 104 c that opens upward is formed in the shaft portion 104 b that protrudes from the upper surface of the shaft gear 104. A thread groove is formed on the inner peripheral surface of the recess 104c. On the central axis L of the shaft gear 104, a through hole 104e communicating with the recess 104c is formed. The inner ring 106b of the bearing 106 is fitted and fixed to the shaft portion 104b. A thread groove is formed on the outer peripheral surface of the shaft portion 104b at a position above the bearing 106. The outer ring 106 a of the bearing 106 is fitted and fixed in a recess 108 formed in the lower surface of the upper casing 80. The shaft portion 104 b protrudes upward through a through hole 111 formed in the upper casing 80. A bearing fixing nut 117 is screwed into the shaft portion 104 b at a position above the bearing 106 with the flat washer 113 interposed therebetween, whereby the inner ring 106 b of the bearing 106 is fixed to the shaft gear 104.

  As shown in FIG. 6, in a state where the rotation drive mechanism 74 is attached to the lower surface of the top plate 50 via the rotation drive mechanism attachment jig 76, the shaft portion 104 b is rotatable in a hole 50 a formed in the top plate 50. The upper end surface 104d of the shaft portion 104b protrudes upward from the upper surface 50b of the top plate 50. In this state, the bottom plate 115 of the rotating portion 46 is placed on the upper end surface 104d of the shaft portion 104b. As shown in FIG. 7, a round hole 115 a is formed at the center of the plane of the bottom plate 115. The lower portion 121b of the nozzle mounting nipple 121 is inserted into the round hole 115a. Screw grooves are formed on the outer peripheral surfaces of the lower portion 121b and the upper portion 121a of the nozzle mounting nipple 121, respectively. The nozzle mounting nipple 121 is formed with a hole 121c passing through the central axis thereof. An O-ring 123 is mounted in the vicinity of the lower end portion of the lower portion 121b of the nozzle mounting nipple 121. A detent nut 119 is screwed into the outer peripheral surface of the lower portion 121 b of the nozzle mounting nipple 121. The lower portion 121b of the nozzle mounting nipple 121 is fixed by screwing into the recess 104c of the shaft portion 104b. In this state, by rotating the locking nut 119 downward and tightening, the bottom plate 115 of the rotating portion 46 is strongly tightened between the upper end surface 104d of the shaft portion 104b and the lower surface of the locking nut 119. As a result, the rotating portion 46 is connected and fixed to the shaft portion 104b.

  A recess 131 is formed in the lower surface of the lower casing 82, and an air motor 133 is inserted into the recess 131 and fixed with a motor lock nut 135. A gear 139 is mounted on the rotation shaft of the air motor 133. The gear 139 protrudes above the lower casing 82 and meshes with the gear teeth 141 of the shaft gear 104. The air motor 133 is rotationally driven by the air supplied from the air hose 45. When the air motor 133 is driven, the shaft gear 104 meshed with the gear 139 rotates, and the rotating portion 46 connected and fixed to the shaft gear 104 rotates around the axis L.

  Next, the configuration of the rotating unit 46 will be described. As shown in FIG. 6, the rotation part 46 is comprised by the metal frame 65 and the injection part 67 arrange | positioned in the inside. As shown in FIG. 9, the frame body 65 includes a bottom plate 115 having a planar quadrilateral shape (FIG. 8), columns 69, 71, 73, 75 that are erected and fixed at respective corner positions of the plate 115, And an upper plate 116 having a planar rectangular shape fixed to the upper ends of 73 and 75. The injection unit 67 includes a nozzle attachment 125, a spray nozzle tube 39 that is erected and fixed to the nozzle attachment 125, and a spray nozzle 40 that is attached to the upper end portion of the spray nozzle tube 39 with the central axis of the injection direction facing the horizontal direction. It consists of The nozzle attachment 125 is fixed to the upper portion 121a of the nozzle mounting nipple 121 by inserting a packing 122 between the nozzle attachment nipple 121 and screwing it over from the outside. The spray nozzle tube 39 is vertically fixed with a nut portion 39a at the lower end portion inserted into the outlet portion 125a of the nozzle attachment 125 with a packing 124 therebetween, screwed from the outside, and screwed.

  With the above configuration, when the air motor 133 is driven, the shaft gear 104 rotates about the axis L, and accordingly, the entire rotation unit 46 that is coaxially connected to the shaft gear 104 rotates about the axis L. . The paint pumped through the paint hose 49 (FIG. 7) includes a hole 104e formed on the central axis L of the shaft gear 104, a hole 121c formed on the central axis of the nozzle mounting nipple 121, and a nozzle attachment. 125 is supplied to the spray nozzle 40 through the spray nozzle tube 39, and a predetermined injection range Z (injection angle) from the spray nozzle 40 in the vertical direction with the central axis C (FIG. 6) in the injection direction directed horizontally. Injected at α). By spraying the paint from the spray nozzle 40 while rotating the rotating part 46, the entire circumference of the vent pipe inner peripheral surface 20b can be painted. At this time, the relative rotation portion between the lower shaft portion 104a of the shaft gear 104 and the lower casing 82 is sealed by the gland packing 92, so that the paint is prevented from leaking outside from this portion.

  Next, the detailed structure of the suspension support part 48 is demonstrated with reference to FIG. The suspension support portion 48 suspends and supports the rotation portion 46 and releases the relative rotation of the rotation portion 46 with respect to the wire rope 38 to suppress the wire rope 38 from twisting. A round hole 116 a is formed in the center of the upper plate 116 of the rotating portion 46. On the upper and lower surfaces of the upper plate 116, thrust bearings 147 and 148 are arranged coaxially with the round hole 116a. Here, the thrust bearings 147 and 148 are constituted by single type thrust ball bearings. The single thrust ball bearing 147 has a structure in which a ball 147c is sandwiched between two upper and lower washer disks 147a and 147b. Similarly, the single thrust ball bearing 148 has a structure in which a ball 148c is sandwiched between two upper and lower washer disks 148a and 148b. A flat washer 149 and nuts 151 and 153 are disposed on the upper surface of the single thrust ball bearing 147. A flat washer 155 and nuts 156 and 157 are arranged on the lower surface of the single thrust ball bearing 148. The hanging bracket 159 with a ring is for hooking the hook 126b (FIG. 4) of the pulley 126 with the hook suspended from the wire rope 38. The hanging bracket 159 with a ring includes a ring 159a and a screw portion 159b connected under the ring 159a. The hanging bracket 159 with a ring is formed by screwing nuts 153 and 151 into a threaded portion 159b, and then screwing the threaded portion 159b into a flat washer 149, a single thrust ball bearing 147, a round hole 116a in the upper plate 116, a single thrust ball bearing 148, By sequentially passing through the washer 155 and further screwing and tightening nuts 156 and 157 into the screw part 159b, the screw part 159b is coupled to the rotating part 46. In this state, the lower washer 147b of the single thrust ball bearing 147 and the upper washer 148a of the single thrust ball bearing 148 are fixed and integrated on the rotating portion 46 side (therefore, the washer 147b, 148a). Is a component on the rotating unit 46 side). Further, the upper washer 147a of the single thrust ball bearing 147 and the lower washer 148b of the single thrust ball bearing 148 are fixed to and integrated with the hanging bracket 159 side with the ring. Since the upper and lower washer 147a, 147b of the single type thrust ball bearing 147 are relatively rotatable, and the upper and lower washer 148a, 148b of the single type thrust ball bearing 148 are relatively rotatable, the rotating portion 46 is a hanging bracket 159 with a ring. On the other hand, it can rotate relative to the axis L.

  According to the above configuration, as shown in FIG. 4, the rotation support portion 44 is below the spray range Z of the spray nozzle 40, and the suspension support portion 48 is above the spray range Z of the spray nozzle 40. Therefore, the rotation support portion 44 and the suspension support portion 48 do not interfere with the spraying of the paint 42 by the spray nozzle 40. Moreover, since the coating machine 36 performs coating while descending, the rubber caster 64 does not travel in the painted location. Further, if the spray dust 42a falls to the lower part of the vent pipe 20 during coating, adheres to an unpainted portion of the inner peripheral surface 20b and hardens, and then is coated on the coating defect, It becomes. On the other hand, in this coating machine 36, the top plate 50 of the rotation support portion 44 constitutes a spray dust receiving member, and receives the spray dust 42a descending during painting just below the injection range Z, so that the spray dust 42a is vented. It can prevent adhering to the unpainted location of the pipe inner peripheral surface 20b. Note that spray dust 42a adheres to a short vertical region d (FIG. 4) between the lower end position of the spray range 40 of the spray nozzle 40 and the top plate 50 on the inner peripheral surface 20b of the vent pipe. Since the regular coating is immediately applied as the coating machine 36 is lowered, even if the spray dust 42a is attached, the regular coating is overcoated before it is cured. As a result, since the spray dust 42a adhering to the area | region d is integrated with regular coating, it does not become a coating defect. For this reason, the coating machine 36 can prevent a coating defect from occurring.

  FIG. 10 shows the detailed configuration of the hoisting device. The hoisting machine 32 is disposed on the diaphragm floor 16. As the hoisting machine 32, for example, an air driven variable speed hoisting machine can be used. In this case, a control box 160 with an air regulator is used to stabilize the winding / lowering speed. A wire rope 38 is unwound from the hoisting machine 32. A girder member 161 constituting a pulley mounting jig is detachably mounted on the cover plate 26 fixedly disposed on the upper end portion of the legs 24 fixed on the diaphragm floor 16. FIG. 11A is a plan view showing a state where the girder member 161 is mounted on the cover plate 26. The girder member 161 is inserted into a space 28 between the lower surface of the cover plate 26 and the upper end opening 20 a of the vent pipe 20 through a gap 30 between the legs 24. The girder member 161 is detachably fixed to the opposite peripheral edge positions of the cover plate 26 with mounting brackets 163 and 164. That is, at the position on the one end side of the girder member 161, the mounting bracket 163 sandwiches the peripheral edge of the cover plate 26 between the upper surface of the girder member 161 and is fixed with the screw 166. Further, at the position on the other end side of the girder member 161, the attachment member 164 sandwiches the peripheral edge portion of the position where the cover plate 26 faces between the upper surface of the girder member 161, and is fixed with screws 168. The mounting position of the mounting bracket 163 on the girder member 161 is fixed, but the mounting position of the mounting bracket 164 is configured by a long hole in which a hole 164a into which the screw 168 is inserted extends in the longitudinal direction of the girder member 161. Therefore, the girder member 161 can be moved by a predetermined amount in the longitudinal direction.

  The structure of the girder member 161 will be described. FIG. 11A shows the planar structure of the girder member 161 mounted on the cover plate 26. Moreover, CC sectional view taken on the line of Fig.11 (a) is shown in FIG.11 (b). The girder member 161 is formed of a metal square pipe, and openings 161a and 161b are formed on the upper and lower surfaces of the central portion. In the girder member 161, two-wheel pulleys 35a and 35b are accommodated at positions where the openings 161a and 161b are formed. The two-wheel pulleys 35 a and 35 b are rotatably supported by a shaft portion 132 that is attached so as to penetrate between both side surfaces of the girder member 161. The wire rope 38 drawn out from the hoisting machine 32 (FIG. 10) is passed through the girder member 161 via the guide roller 165 (FIG. 10) and the guide roller 167 of the girder member 161, and hung on the pulley 35a. Then, it is suspended in the vent pipe 20 and further hung on the pulley 126a of the hooked pulley 126, and then folded back and hung on the pulley 35b. The end of the wire rope 38 is positioned at an appropriate position of the girder member 161. Are fastened to fasteners 136 arranged in Thereby, the pulley 126 with a hook is suspended at the position of the central axis L of the vent pipe 20. The hook 126b of the pulley 126 with the hook is hung on the ring 159a of the hanging metal fitting 159 of the hanging support portion 48 (FIG. 9). According to the above configuration, the coating machine 36 can be moved in the vertical direction in the vent pipe 20 by reversibly driving the hoisting machine 32.

  A metal plate 134 is disposed in the girder member 161 at a position between the pulleys 35a and 35b. The metal plate 134 is rotatably supported by the shaft portion 132. The lower part of the metal plate 134 protrudes downward from the opening 161 b on the lower surface of the girder member 161. A contact portion 134 a is formed at the lower end portion of the metal plate 134. The metal plate 134 is normally kept in a state where the contact portion 134a is disposed on the lower side (the state shown in FIG. 10) due to its own weight. When the hoisting machine 32 is driven and the wire rope 38 is wound up to the position of the girder member 161, the upper end portion of the pulley 126 with the hook comes into contact with the abutting portion 134a. The metal plate 134 rotates around the shaft 162 while the upper end portion of the pulley 126 is in contact with the contact portion 134 a, and the hooked pulley 126 passes through the opening 161 b on the lower surface of the beam member 161 and enters the beam member 161. In the space 161d. FIG. 12 shows a state in which the hooked pulley 126 is housed in the girder member 161. In this state where the hooked pulley 126 is housed in the girder member 161, the girder member 161 passes through the gap 30 between the legs 24 and between the lower surface of the cover plate 26 and the upper end opening 20 a of the vent pipe 20. Or is pulled out through the space 28 and the gap 30.

  A magnet 128 a is disposed on one side of the metal plate 134. On the other hand, a magnetically sensitive switch 128b such as a reed switch is disposed on an appropriate pedestal 129 on the inner surface of the girder member 161. The magnet 128a and the magnetic sensitive switch 128b constitute a magnetic switch 128. The magnetic switch 128 is used to automatically stop the winding operation of the hoisting machine 32. That is, in the state where the upper end portion of the hooked pulley 126 is not in contact with the contact portion 134a of the metal plate 134, the contact portion 134a is disposed on the lower side of the metal plate 134 by its own weight as described above. The state (the state shown in FIG. 10) is maintained. At this time, the magnet 128a and the magnetic sensitive switch 128b face each other, and the magnetic switch 128 is turned on, and the hoisting machine 32 can be driven. When the upper end of the hooked pulley 126 abuts against the abutting portion 134a of the metal plate 134 and the metal plate 134 rotates about the shaft 162, the magnet 128a and the magnetically sensitive switch 128b do not face each other (state in FIG. 12). The magnetic switch 128 is turned off, and the drive of the hoisting machine 32 is forcibly stopped (for example, if the hoisting machine 32 is an air-driven hoisting machine, the electromagnetic valve disposed in the middle of the air hose is shut off) By doing so, the hoisting machine 32 can be stopped.) Thereby, failure of the hoisting machine 32 due to continued driving of the hoisting machine 32 can be prevented. In addition, by attaching a mark to the predetermined position of the wire rope 38 with a tape or the like in advance, the operator of the hoisting machine 32 visually recognizes the mark so that the height position of the coating machine 36 in the vent pipe 20 can be determined. I can know. For example, when the spray nozzle 40 is at the coating start position at the upper end of the vent pipe 20 and when the spray nozzle 40 is at the coating end position at the lower end of the vent pipe 20, a predetermined observation position (for example, a wire rope) is used. Marks are placed on the positions on the wire rope 38 that are positioned at positions where the position 38 is discharged from the end of the girder member 161, and the operator of the hoisting machine 32 attaches to the wire rope 38 at the time of painting. By visually recognizing that the mark has reached the observation position and stopping the hoisting machine 32, the spray nozzle 40 can be stopped at the painting start position and the painting end position, respectively.

  The system configuration of the entire coating apparatus for operating the coating machine 36 will be described with reference to FIG. Here, the case where the airless coating method is used will be described. The airless coating method is a method in which a paint is pressurized with an airless pump, sprayed from a spray nozzle (airless nozzle) through a paint hose, and applied as a mist. In the reactor building 10 of FIG. 2, a carriage 171 shown in FIG. 13 is disposed on the floor 172 in the chamber 170 outside the entrance / exit 169 leading to the suppression chamber 14. Each hose 41, 43, 45 and signal line 59 connected to the coating machine 36 is led from the chamber 170 through the entrance / exit 169 into the suppression chamber 14. A bellows type airless pump 173, an integrated control box 175, and the like are arranged on the carriage 171. A paint 42 is accommodated in the paint tank 177. One end of a paint hose 181 is inserted into the paint 42. A 40 mesh strainer 183 is attached to the tip of the paint hose 181. The other end of the paint hose 181 is connected to the inlet 185 of the airless pump 173. A paint hose 41 is connected to the discharge port 187 of the airless pump 173. The airless pump 173 is an air-driven airless pump, is driven by air supplied from a compressor (not shown) through an air hose 180, and discharges the paint flowing in from the inlet 185 from the outlet 187 at high pressure. And supplied to the paint hose 41.

  The paint supplied to the paint hose 41 is sequentially filtered by the 80 mesh strainer 191 and the 100 mesh strainer 193. An inlet pressure gauge 195 is disposed on the inlet side of the 80 mesh strainer 191, and an outlet pressure gauge 197 is disposed on the outlet side of the 100 mesh strainer 193. An operator looks at the indicated values of both pressure gauges 195 and 197 during painting, and when the pressure difference becomes larger than a predetermined value, at least one of the strainers 191 and 193 is clogged. And the operation of the airless pump 173 is stopped. Then, the valves 190 and 192 are opened, the inside of the strainers 191 and 193 is washed, and the drainage is discharged to the drainage tanks 198 and 200 via the hoses 194 and 196. When the clogging in the strainers 191 and 193 is eliminated by cleaning, the valves 190 and 192 are closed, the airless pump 173 is restarted, and the painting is restarted. A flow meter 199 for measuring the flow rate of the paint is disposed on the downstream side of the strainer 193. The flow rate of the paint is determined by the type of the spray nozzle 40 (airless nozzle) if the pressure of the driving air of the airless pump 173 is constant. As described above, the paint flowing out from the flow meter 199 is sprayed from the spray nozzle 40 through the air operation valve 70, the 100 mesh strainer 72, the rotation drive mechanism 74, and the rotation unit 46 of the coating machine 36.

  The control box 175 includes a rotation switch 202 that switches the rotation / stop of the rotation unit 46, a rotation adjustment regulator 204 that adjusts the rotation speed of the rotation unit 46, and rotation detection of the rotation unit 46 by a rotation sensor (magnetic switch) 57. , A rotation meter 206 for displaying the rotation speed of the rotation unit 46 as a numerical value, a rotation confirmation lamp 208 for displaying rotation detection of the rotation unit 46 by the rotation sensor (magnetic switch) 57 (flashing once per rotation), air operation A spray switch 209 for switching the spraying / stopping of the paint 42 from the spray nozzle 40 by opening / closing the valve 70, an air pressure gauge 213 for displaying the pressure of air supplied from the air hose 211, and the like are provided. The air hose 211 is supplied with air for switching operation of the air operation valve 70 and air for rotating the air motor 133 from the compressor.

  In the control box 175, when the operator instructs “rotation” with the rotation switch 202, air is supplied to the air hose 45, the air motor 133 is driven, and the rotating unit 46 rotates. The rotation of the rotating unit 46 is detected by the rotation sensor 57, and based on the detection, the rotation confirmation lamp 208 blinks at a rate of once per rotation. Further, based on the detection, the number of revolutions is calculated by the calculator in the control box 175, and the calculation result is displayed numerically on the tachometer 206. The operator can confirm that the rotating unit 46 is rotating by watching the blinking of the rotation confirmation lamp 208. In addition, the operator can adjust the rotation speed of the rotating unit 46 to a predetermined target value by operating the rotation adjusting regulator 204 and adjusting the air flow rate while watching the display on the tachometer 206. it can. When the operator commands “stop” with the rotation switch 202, the supply of air to the air hose 45 is stopped, the air motor 133 is stopped, and the rotation of the rotating unit 46 is stopped.

    In the control box 175, when the operator instructs “injection” with the spray switch 209, air is supplied to the air hose 43, the air operation valve 70 is opened, and the coating material 42 is injected from the spray nozzle 40. When the operator instructs “stop” with the spray switch 209, the supply of air to the air hose 43 is stopped, the air operation valve 70 is closed, and the spraying of the paint 42 from the spray nozzle 40 is stopped.

  An example of the painting operation of the vent pipe inner peripheral surface 20b by the hoisting device of FIG. 10 and the coating device of FIG. 13 described above will be described. The painting operation is performed in the suppression chamber 14 where the operator in the dry well 12 who operates the hoisting machine 32 and the operation of attaching / detaching the wire rope 38 to / from the coating machine 36 and the guiding operation into the vent pipe 20 of the coating machine 36 are performed. And the worker in the room 170 who operates the control box 175 cooperate with each other. First, an operator in the suppression chamber 14 places a coating machine 36 on the floor 34 below the vent pipe 20. An operator in the dry well 12 operates the control box 160 of the hoisting machine 32 to lower the wire rope 38. When the hooked pulley 126 descends to the vicinity of the floor 34 in the suppression chamber 14, an operator in the suppression chamber 14 hooks the hook 126 b of the hooked pulley 126 on the ring 159 a of the suspension support portion 48 of the coating machine 36. In this state, the hoisting machine 32 is wound up and the coating machine 36 is lifted into the vent pipe 20. When the operator in the dry well 12 confirms that the spray nozzle 40 has reached the coating start position by the mark attached to the wire rope 38, the operator stops the hoisting machine 32.

  Next, when an operator in the chamber 170 instructs “rotation” with the rotation switch 202 of the control box 175, the air motor 133 is activated and the rotation unit 46 starts to rotate. At this time, since the rubber caster 64 on the upper side of the rotation support portion 44 is in press contact with the vent pipe inner peripheral surface 20b, the rotation of the rotation support portion 44 is suppressed. Further, the lower rubber caster 58 of the rotation support portion 44 contacts the vent pipe inner peripheral surface 20b, and the inclination of the rotation support portion 44 is suppressed. Further, since the rotation of the rotating portion 46 is released by the suspension support portion 48, the wire rope 38 is prevented from being twisted.

  In this state, an operator in the chamber 170 operates the rotation adjustment regulator 204 while looking at the tachometer 206 to adjust the rotation speed of the rotating unit 46 to a predetermined target value. When this adjustment is finished, the spray switch 209 is used to command “injection”. As a result, the air operation valve 70 is opened, and the paint 42 is sprayed from the rotating spray nozzle 40 to start painting the entire circumference of the vent pipe inner peripheral surface 20b. Simultaneously with the start of painting, the operator in the dry well 12 drives the hoisting machine 32 in the lowering direction at an appropriate speed according to the rotational speed of the spray nozzle 40. Thereby, the coating machine 36 descends slowly, and the vent pipe inner peripheral surface 20b is coated in order from the top without any gaps by overlapping the coating range in the vertical direction in a spiral manner for each turn.

  When the painting is completed up to the lower end portion of the vent pipe 20, “stop” is commanded by the spray switch 209. Thereby, the air operation valve 70 is closed, and the spraying of the paint 42 from the spray nozzle 40 is stopped. Then, the wire rope 38 is further lowered to land the coating machine 36 on the floor 34. Thereby, the coating of the vent pipe inner peripheral surface 20b is completed. The coating thickness can be adjusted by the rotation speed of the rotating unit 46, the amount of paint discharged, and the lowering speed of the hoisting machine 32. When the painting is completed, the hooked pulley 126 is removed from the painting machine 36, the wire rope 38 is wound up and collected, and the girder member 161 is removed from the cover plate 26. This completes the painting work for one vent pipe 20 and repeats the painting work for the other vent pipes 20 in the same manner.

  In the above-described embodiment, the rotation relief mechanism of the rotating portion 46 is configured by the thrust bearings 147 and 148. However, instead of or in combination with this, the rotation escape mechanism is configured on the pulley 126 with hook. You can also. In this case, the hooked pulley 126 forms a part of the suspension support portion. A specific example of a pulley 126 with a hook provided with a rotation escape mechanism is shown in FIGS. The pulley 126 with a hook in FIG. 14 includes two-wheel pulleys 126a and 126a. A hook 126b is suspended from a frame member 126c that supports the pulleys 126a and 126a via a bearing 126d. The pulley 126 with a hook of FIG. 15 is provided with one pulley 126a. A hook 126b is rotatably suspended from a frame member 126c that supports the pulley 126a via a bearing 126d. Moreover, it can replace with the pulley 126 with a hook, and can also use a suspension tool without a pulley. FIG. 16 shows an example of a pulleyless suspension. In the hookless suspension 126 ', hooks 126f and 126g are attached to the top and bottom of the frame member 126e via bearings 126h and 126i, respectively. A wire rope 38 is hung on the upper hook 126f, and a lower hook 126g is hung on a ring 159a of a hanging metal fitting 159 (FIG. 9).

It is a schematic longitudinal cross-sectional view which shows embodiment of the coating method of this invention, and is a figure which shows the procedure which coats the internal peripheral surface 20b of the vent pipe 20 of the structure shown to FIG. 2 and FIG. It is a longitudinal cross-sectional view which shows the structural example of the nuclear reactor containment vessel which can apply this invention. It is the perspective view and longitudinal cross-sectional view which show the structure of the location where the vent pipe 20 of the upper surface of the diaphragm floor 16 of FIG. 2 penetrates. It is a front view which shows embodiment of the coating machine of this invention. It is an AA arrow line view of FIG. FIG. 6 is a front view (perspective view) showing a detailed configuration of a rotation drive mechanism 74. FIG. 7 is an exploded front sectional view of the rotary drive mechanism 74 of FIG. 6. It is BB arrow sectional drawing of FIG. FIG. 6 is an exploded view showing detailed configurations of a rotating part 46 and a suspension support part 48. It is a figure which shows the detailed structure of a winding apparatus. FIG. 11 is a plan view showing a state where a girder member 161 is attached to the cover plate 26 of FIG. 10. FIG. 6 is a side view (perspective view) showing a state in which a hooked pulley 126 is housed in a girder member 161. It is a figure which shows the system configuration | structure of the whole coating apparatus for driving the coating machine. It is the front view and side view which show an example of the pulley 126 with a hook which comprised the rotation escape mechanism. It is the front view and side view which show another example of the pulley 126 with a hook which comprised the rotation escape mechanism. It is the front view and side view which show an example of the hook-less hanging tool replaced with the pulley 126 with a hook.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Reactor containment vessel, 12 ... Dry well, 14 ... Suppression chamber, 16 ... Diaphragm floor, 20 ... Vent pipe, 20a ... Vent pipe upper end opening, 20b ... Vent pipe inner peripheral surface, 24 ... Leg, 26 ... Cover plate 28 ... Space between the upper end opening of the vent pipe and the lower surface of the cover plate, 30 ... Clearance between the legs, 32 ... Hoisting machine, 35, 35a, 35b ... Pulley (rope hook), 36 ... Coating machine 38 ... Wire rope (rope), 40 ... Spray nozzle (nozzle), 42 ... Paint, 42a ... Spray dust, 44 ... Rotation support part, 46 ... Rotation part, 48 ... Hanging support part, 50 ... Top plate (spray) Dust receiving member), 64 ... Rubber caster (pressing contact member), 74 ... Rotation drive mechanism, 161 ... Girder member (rope hook mounting jig), 163, 164 ... Mounting bracket, L ... Vent pipe Mandrel, the rotation axis of the rotating unit, Z ... injection range.

Claims (6)

The vent pipe is vertically arranged through the diaphragm floor that divides the dry well and the suppression chamber, the upper end of the vent pipe is opened to communicate with the dry well, and the lower end of the vent pipe is opened to communicate with the suppression chamber. A plurality of legs are fixedly disposed on the upper surface of the diaphragm floor so as to surround the periphery of the upper end opening of the vent pipe, and a cover plate is disposed above the upper end opening of the vent pipe. The vent pipe is fixedly disposed so as to cover the upper end opening of the vent pipe with a space therebetween, and the upper end opening of the vent pipe passes through the space between the lower surface of the cover plate and the gap between the legs. In a reactor containment vessel having a structure communicating with a well, a method of painting the inner peripheral surface of a vent pipe,
A hoisting machine is arranged in the dry well, a coating machine is arranged in the suppression chamber, a rope hanging tool is arranged below the cover plate,
The hoisting machine rope is passed through the gap between the legs and the space between the lower surface of the cover plate and the upper end opening of the vent pipe, and is hung on the rope hook and through the vent pipe to the coating machine. Concatenate,
Hoisting the rope, hoisting the coating machine in the vent pipe,
A method of coating the inner peripheral surface of the vent pipe by injecting paint from the nozzle of the coating machine toward the inner peripheral surface of the vent pipe and moving the vertical position of the coating machine by the hoisting machine. After connecting the hoisting machine rope to the coating machine,
Hoisting the rope, hoisting the coater to near the upper end in the vent pipe,
The method according to claim 1, wherein the inner peripheral surface of the vent pipe is coated by gradually lowering the coating machine while spraying the paint from the nozzle of the coating machine in the entire circumferential direction of the inner peripheral surface of the vent pipe.   The rope hook is attached to a rope hook attachment jig, and the rope hook attachment jig is inserted into a space between the lower surface of the cover plate and the upper end opening of the vent pipe through a gap between the legs. The method according to claim 1 or 2, wherein the rope hook attachment jig is detachably fixed to the peripheral edge of the cover plate at a plurality of locations by means of attachment fittings.   A spray dust receiving member having a size that substantially closes the inner diameter of the vent pipe is mounted and disposed below the spray range of the nozzle of the coating machine, and the spray dust receiving member is lowered together with the coating machine during painting. The method according to any one of claims 1 to 3, wherein the descending spray dust is received by the spray dust receiving member. In a reactor containment vessel having a structure in which a vent pipe is vertically arranged through a diaphragm floor that divides a dry well and a suppression chamber, the inner circumference of the vent pipe is suspended in a vent pipe by a rope. A painting machine for painting,
A rotation support unit, a rotation unit rotatably connected to an upper side of the rotation support unit, and an upper side of the rotation unit coaxially connected to a rotation axis of the rotation unit so as to be relatively rotatable with the rotation unit. A suspension support part,
The rotation support portion presses and contacts the pressing contact member with the inner peripheral surface of the vent pipe at a plurality of locations in the circumferential direction, and suppresses rotation of the rotation support portion itself in the direction around the vent tube axis. Allowing movement in the direction of the vent pipe axis, and rotating the rotary part with a rotary drive mechanism, supporting the rotary part in a state where the rotary axis substantially coincides with the position of the axis of the vent pipe,
The rotating portion includes a nozzle that sprays paint toward the inner peripheral surface of the vent pipe, and in accordance with the rotation of the rotating portion, sprays the paint sprayed from the nozzle in the entire circumferential direction of the vent pipe inner peripheral surface. ,
The suspension support unit is coupled to the rope and supports the rotation unit so that the rotation unit can rotate relative to the rotation axis.
A coating machine for an inner peripheral surface of a vent pipe of a reactor containment vessel, wherein the rotation support portion and the suspension support portion are arranged outside the injection range of the nozzle.   The coating machine according to claim 5, wherein the rotation support portion is provided with a spray dust receiving member having a size that substantially blocks the inner diameter of the vent pipe at a position below the spray range of the nozzle.

Images